Flooding of a building may cause significant damage and long-term detriment to a building, irrespective of damage caused to any contents of the buildings. It may therefore be desirable to have adequate flood protection suitable for preventing flood water from entering the building. Flood water may enter a building through any building element forming an opening in the building, such a door or a window. A door at ground level may be the first point of entry for flood water. Even when fully closed, it may still be possible for flood water to flow past the door and enter the building.
A known form of permanent flood protection involves a flood seal provided in the door such that the door is sealed whenever it is shut. More precisely, a gasket formed from a resilient material may be provided on the door frame and, alternatively or additionally, a similar gasket may be arranged on the door leaf. Upon closing the door, the gasket seals a gap that is formed between the door leaf and the frame. However, water may still enter the building by seeping through the seal formed by the gasket. While a larger gasket may reduce seepage, such an arrangement may require increased force for shutting the door. For a low threshold door, however, a larger gasket is not an option as a low threshold door has a maximal height according to building regulations.